Apparatus for continuous coating of elongated articles



July 27, 1965 F. E. TURNER 3,196,828

APPARATUS FOR CONTINUOUS COATING OF ELONGATED ARTICLES Filed Sept. 27,1962 9 Sheets-Sheet l lNVENTOR FRANK E. TURNER W 1 /ATTORNHEYS.

y 7, 1965 F. E. TURNER 3,196,828

APPARATUS FOR CONTINUOUS COATING OF ELONGAIED ARTICLES Filed Sept. 27,1962 9 Sheets-Sheet 2 ywmw 1 E. 5; :1 u

?\ g INVENTOR. FRANK E. TURNER 1 8W W film/M YLATTOENEYS' July 27, 1965F. E. TURNER APPARATUS FOR' CONTINUOUS COATING OF ELONGATED ARTICLES 9Sheets-Sheet 3 Filed Sept. 27, 1962 .INVENTOR. FRANK L. TURNER.

ATTORNEYS July 27, 1965 F. E. TURNER 3,196,828

APPARATUS FOR CONTINUOUS COATING OF ELONGATED ARTICLES Filed Sept. 27,1962 9 Sheets-Sheet 4 INVENTOR.

FRANK E. TURNER z; iTToRNsw y 27, 1965 F. TURNER 3,196,828

APPARATUS FOR CONTINUOUS COATING OF ELQNGATED ARTICLES Filed Sept. 27,1962 9 Sheets-Sheet 5 INVENTOR F24 M: Z. 752N512 A TTOF/VEYJ.-

July 27, 1965 F. E. TURNER 3, 95,8

APPARATUS FOR CONTINUOUS COATING OF ELONGATED ARTICLES Filed Sept. 27,1962 e Sheets-Sheet e INVENTOR fen/w .5 Tut/me ATTORNEYS.

July 27, 1965 F. E. TURNER 3,

APPARATUS FOR CONTINUOUS COATING 0F ELONGATED ARTICLES Filed Sept. 27,1962 S'SheetS-Sheet 7 July 27, 1965 v F. E. TURNER 3, ,8

APPARATUS I 'QR CONTINUOUS COATING 0F ELONGATED ARTICLES Filed Sept. 27,1962 9 Sheets-Sheet 8 I N VENTOR. E64 NK :7 Wax/5e United States PatentE. Co

This invention relates to the treatment of elongated article" withliquid material and more particularly to an improved apparatus for usein the continuous hot galvanizing of metal products such as pipe, bars,shapes, etc.

This application is a continuation-in-part of my copending United Statespatent application Serial No. 791,- 612, filed February 6, 1959, nowPatent No. 3,063,409.

lin the accompanying drawings and the following specification there isdescribed and illustrated an apparatus for hot galvanizing metal pipe,but it will be understood that the invention may advantageously beemployed in numerous other applications where it is desired to treatelongated articles such as pipe, bars, shapes, etc., in a liquid hath.Accordingly where reference is made to galvanizing herein, it isintended to include not onl galvanizing per se but also other coatingoperations such as the application of paint, enamel, cleaning orpickling solutions, etc., and where reference is made to pipe it isintended to include other elongated articles such as bars, shapes, etc.

in galvanizing steel pipe it is common practice to submerge the pipe ina bath of molten zinc so that both the inner and outer surfaces of thepipe are completely covered, The lengths of pipe are then withdrawn anddrained. The pipes have customarily been manually lifted from thegalvanizing bath and brought into engagement with suitable rolls orconveyors which remove the pipes from the tank.

lt an object of the present invention to provide, in a fully automaticcontinuous pipe galvanizing machine or the like wherein the pipes orother elongated articles mainain the same positive relation to eachother throughout the entire process, improved means for withdrawing pipefromthe coating tank, holding the pipe and removing excess zinc or othercoating material therefrom, and transferring the pipes in propersequential order and spacing to a conveyor or the like, all in acontinuous and automatic manner.

The above and other objects of the invention will appear from thefollowing description of an apparatus for galvanizing steel pipe or thelike in which the present invention is incorporated, reference beingmade to the accompanying drawings in which:

FIGURE 1 is a plan view, partly in horizontal cross section,illustrating the invention as incorporated in pipe galvanizingapparatus;

FEGURE 2 is an enlar ed vertical cross-sectional view takensubstantially on line 22 of FIGURE 1;

PEGURE 3 is a vertical cross-sectional view taken substantially on line33 of FIGURE 2, the pipe conveying and sinking screws, however, beingillustrated in the positions they assume as a pipe is being movedendwise out of the galvanizing bath;

FIGURE 4 is an end elevational view taken substantiaily on line l-4- ofFIGURE 1 and illustrating the internal and external coating controlstations and the magnetic roll conveyor means for removing coated pipefrom the galvanizing tank;

FIGURE 5 is a vertical cross-sectional view taken substantially on line5-5 of FlGURE 1 and illustrating the indexing transfer means for movingpipe from the magnetic roll conveyor to the internal coating controlstation, the water bosh, the spray coating unit, etc.;

FIGURE 6 is a view generally similar to FIGURE 4 but illustrating amodified arrangement of the electromagnetic drag out rolls and indexingtransfer units for handling the pipes as they are withdrawn from thecoating bath; and

ElGURE 7 is an enl rged cross-sectional view, taken substantially online 77 of FIGURE 6, illustrating the angular relation and mode ofoperation of the transfer racks to convey the coated pipes from theelectromagnetic rolls to the internal coating control station and theconveyor that takes the pipes to the water bosh;

FIGURE 8 is a diagrammatic view of the transfer racks and supportingarms shown in FIGURE 7 but in their positions when the pipes aretransferred from one set of racks to the other;

ElGURE 9 is an elevational view generally similar to FIGURES 4 and 6 butillustrating another form of my indexing transfer mechanism;

FIGURE 10 is a plan view taken substantially on line 1tllil of FEGURE 9;and

EEGURE 11 is an enlarged cross-sectional view taken substantially online lit-ll of FIGURE 10.

Referring particularly to EEGURES l and 2, the illustrated automaticcontinuous pipe galvanizing line in which the present invention isincorporated includes a loading rack comprising a plurality of inclinedskid members 1 adapted to receive bundles of pipe from storage orprevious processing operations. On these racks the pipes P are arrangedin a single layer and rolled downwardly by gravity. At the lower end ofthe loading rack the pipes are picked up by an automatic selector unitcomprising a plurality of rotating conveying screws 2 which aresimultaneously driven by suitable gearing and shafting such that theirrotation is in a direction to advance the pipes one at a time in adirection perpendicular to their length. The pitch of the screws 2 andthe shape of the entering ends of the threads thereon is such that oneindividual length of pipe will be removed from the loading skids 1 atevery 360 of rotation of the screws.

Thus the pipes P are removed one at a time from the skids l and areindividually advanced in spaced apart relation in a direction normal toth ir longitudinal axes. From the screws 2 the pipes are delivered to arotating purge chamber 3 in which a varied rotary gas seal and transferwhee i is mounted. As illustrated, tii wheel 4 has a plurality of vanes(six as illustrated) separating the unit into a plurality ofcompartments. As seen in FIG- URE l, the shaft 5 on which the transferwheel 4 is supported is connected by a chain 6 to the drive shaft 2 forthe rotating screws 2, and thus the rotation of the screws 2 issynchronized and interlocked with the transfer Wheel i so that thescrews 2 will successively discharge pipes, one into each of thecompartments formed by the vanes of the transfer wheel. As seen inFKGURE 2, the wheel 4 rotates in clockwise direction and has a fairlyclose fit with the walls of the chamber 3 so that a seal is provided forpreventing undesired entry or escape of atmosphere to or from thefurnace F. A controlled atmosphere of suitable type is preferably causedto enter the compartments formed by the rotating wheel t in the purgechamber 3 to purge the air from the compartments and pipes containedtherein before they enter the furnace.

Immediately beyond the purge chamber and rotating transfer wheel in thedirection of pipe travel is a chain transfer or conveyor comprising aplurality of conveyor chains 7 which extend through the furnace F andcarry the lengths of pipe P therethrough. Screw conveyors may beemployed in place of chains 7 if desired.

Each of the chains 7 is supported on end sprockets 8 and 9 mountedrespectively on shafts l and f1 and is guided by suitable idlersprockets as seen at 12, 13 and 14 in FIGURE 2. Floating counterweightsl maintain the desired tension on the chains 7 which are provided withspaced upstanding lugs 7 which engage the pipes P and move them onsuitable rails or skids 7* through the furnace F. The shaft whichsupports the sprockets 8 is connected to the shaft 5 of the rotarytransfer wheel 4 by chain 15 so that there is positive synchronizationof the automatic selector screws 2, the vanes transfer wheel 4, and thechains 7 or conveyor screws. As the lugs 7 on the individual chains 7are transversely aligned, the pipes will be rolled thereby over theskids 7 in individual sections or compartments in a directionperpendicular to their longitudinal axes. The furnace F, as best seen inFIGURE 2, consists of an entry chamber 16, a heating chamber 17, and anexit end and galvanizing machine housing section 18.

Disposed within the galvanizing chamber section 13 of the furnace F is agalvanizing machine unit which includes a galvanizing kettle 19, adaptedto contain a bath of molten zinc and a pair of spaced pipe conveying andsinking screws generally indicated at S and S. These screws are mountedrespectively on shafts and 21 which extend across the top of thegalvanizing kettle 19 and through the end wall 22 of the furnace F. Asuitable frame structure 23, within the exit end portion 13 of furnaceF, is provided for supporting shafts 2t) and 21, and the feed screws Sand S are so disposed that their entering or pick-up ends 29 (left-handas seen in FIGURE 2) are positioned to take the pipes P one at a time asthey leave skids 7 at the exit end of the conveyor chains 7 and movethem in an advancing series on spaced guides or skids G (see FIGURE 3)toward the galvanizing kettle 19.

The shaft 11 which carries the sprockets 9 for the conveyor chain 7 isconnected through gear box 24 and shaft 25 to gear box 26 which isdriven by the motor 27. Shaft 28 extends from gear box 26 and has gearedconnection to shafts 20 and 21 which support the conveying screws S andS. This interconnection of the conveyor screw drive and the chain driveprovides positive synchronization of the chains '7 and the screws S andS so that at each complete rotation of the screws a length of pipe Pwill be picked up from the conveyors '7 and moved along the guides orskids G by the entering or pick-up portion 29 of screw S and acorresponding portion on screw S.

As clearly seen in FIGURE 3, the pipe guides or skids G are spacedlongitudinally of the galvanizing kettle 19 and are offset from thefront and rear conveying screws S and S. Although the size and contourof the several guides G vary for reasons which will be later referredto, they each have a horizontal entering portion 31, the top edge ofwhich is disposed approximately at the level of the outside of thethread 32 on the pick-up portion 29 of screw S. Just beyond the enteringportions 31 of guides G are downwardly inclined portions 34 which extendinto the galvanizing kettle 19 and have their upper edges sloped toimpart the desired travel of the pipes P into the coating bath in kettle19.

In addition to the pick-up portion 29 of the screws S, it has a flaringor enlarging portion 35 and screw S has a corresponding enlargingportion. The pick-up thread portion 32 of screw S continues on theflaring portion 35 thereof and is indicated at 35.

Just beyond the last pitch of the thread on front screw S is an annulargroove (see FIGURE 3) to which the last pitch of the thread 35 connectsand into which the pipes are moved by said thread. This groove 49 iscircular and has a permanent magnet portion 41 which extends around aportion only of the base of the groove. At the end of the enlargingthread of conveying screw S is a groove 42 formed on an enlarged camportion indicated at 43. A permanent magnet 44 is mounted in the camportion 43 and is effective over the portion of the bottom of the groove42 that is most remote from the shaft 21 (see FIGURE 3).

In the operation of the galvanizing apparatus just described, the pipesP are picked up from the ends of the conveyor chains '7 and aretraversed by conveying screws S and S successively over the horizontalportions 31 of the guides G and down into the galvanizing bath in thekettle 19, the axis of each pipe being tilted during movement into thegalvanizing bath so that the front end enters first and then the rearend being moved down so that the pipe is horizontal when fully submergedin the bath. The pipes are traversed through the bath in a directionperpendicular to their length and ultimately move into the grooves 40and 42 on screws S and S respectively. When a pipe first enters thesegrooves, its axis is substantially horizontal but, as the screw Scontinues to rotate, the rear end of the pipe is further submerged intothe galvanizing kettle to a position such that the pipe will have asubstantial inclination upwardly (for example about 18). As seen inFIGURE 3, as the rear end of the pipe is lowered the front end will beelevated somewhat because it pivots on the screw S a short distance backfrom the front end.

As the conveyor screws S and S rotate, the permanent magnet portions 41and 44 thereof will hold the pipe firmly against the base of the grooves40 and 42 and cause the pipe to be fed longitudinally in the directionof its length. Two permanent magnet rolls and 51 having V-grooves ontheir outer surface to assist in gripping and guiding the pipes, aremounted just beyond conveying screw S in the direction of pipe travel.The axis of roll 51 is vertically otfset from the axis of roll 50 sothat, as a pipe P is moved into its upwardly inclined position by theaction of the cam portion 43 of rear conveying screw S and is movedlongitudinally by magnets 41 and 44 on screws S and S, the forward endof the pipe will engage magnetic rolls 50 and 51. These rolls are drivenby suitable means (not shown) and will continue to move the pipes P inthe direction of their length completely out of the coating liquid inkettle 19 after the magnets 43 and 41 have moved out of contact with thepipes. The rearward inclination of the pipes as they are withdrawn fromkettle 19 insures prompt and complete draining of the coating liquidfrom the pipes back into kettle 19.

The advancing ends of the pipes P, as they are moved out of thegalvanizing kettle 19, are moved into engagement with the lower rolls ofa magnetic roll conveyor unit that is seen in FIGURE 4. This unitincludes at its lowermost end a pair of driven permanent magnet rolls 52and 53 which are aligned with the path of travel of the pipes as theyexit from the galvanizing tank. These rolls 52 and 53 engage and pick upthe pipes as they come along. Supported on an inclined frame 54 are aseries of driven electromagnetic rolls 55, 56, 57 and 53 which areadapted to be energized and tie-energized by suitable electricalconnections and controls (not shown) in a well-known manner.

As seen in FIGURE 4, the pipe P has been moved in the direction of itslength by the permanent magnet rolls 52 and 53 and has engaged theelectromagnet rolls 55, 56, 57 and 58, which are energized at all timesexcept when 'the limit switch 59 is actuated. The depending contactor 59of limit switch 59 extends into the path of the end of the pipe P. Asseen in FIGURE 4, the pipe P has left next single rotation cycle ofthe-support members 63 of indexing transfer units T. I

It will be noted that the magnetic rolls 59, $1, etc. ar illustrated ashaving two pipe receiving grooves therein. These double grooves areprovided so that when double thread screws are used in place of singlethread screws S and S, and the pipes are moved through the galvanizingkettle in pairs, they are handled in pairs as they are moved longitudinaiy out of the galvanizing kettle. In like manner, the suppo g edges ofthe racks 6t 63 and 66 of the indexing tran. as units T are illustratedas having two pipe receiving notches. This also is to permit them to beused with double thread conveying and sinking screws.

In FIGURES 6, 7 and 8 there are illustrated modified forms of magneticdrag-out conveyor and indexing transfer units for taking the ipes fromthe galvanizing kettle, transferring them to the internal blow-outstation, supporting them during the blow out operation, and thentransferring them to the exit conveyor.

As seen in FIGURE 6, permanent magnet rolls 52 and 53 (also seen in F1URE 4-) are disposed above the exit end of the galvanizing kettle 19.They overlie the path of travel of the pipes as they leave the coatingbath. A plurality of magnetic rolls litit), 1431, 1'92, 103 and 164 arerotatably supported on an inclined frame structure 165 and are adaptedto be driven by any suitable means (not shown). These rolls mil-10 i aredisposed to receive the pipes as they leave the rolls 52 and 53, engagethem on the under side thereof, and advance them into the positionindicated at P" in FTGURE 6. A plurality of indexing transfer units Tare also mounted on the inclined frame 1*?)5 between the rolls mid-104.

As best seen in FTGURES 7 and 8, each of the indexing transfer units Tincludes a first or initial movable rack 1% supported for circularorbital movement on the arms 197 and 108 which are mounted on the endsof shafts (not seen in the drawings) projecting from the housing Theshafts which support arms 167 and 103 are driven by suitable means andare interconnected for simultaneous rotation. It will be apparent thateach rack 196 will be moved by its arms lttfl and 1&3 in a circularorbital path when said shafts are rotated. All of the racks 1% areangularly aligned and are maintained in horizontal position at all timesby their supporting arms. The direction of rotation is as indicated bythe arrow in FIGURE 7.

On the opposite sides of the housings N9 from the racks 1&6 a series ofsecond movable racks 116, 111, 112 and are each supported on arms Hi4and 115. As seen in FIGURE 7, the racks 119-113 are of successivelydiminishing height from adjacent the galvanizing kettle 19 outwardly forpurposes that will be later explained. The arms 114 and 2.15 aresupported on shafts 114 and 115 which extend into the housings 139. Whenthese shafts lid and 115 are rotated the racks Mil-113 will move incircular orbital paths in the same direction and at the same rate as theracks M26. Suitably interconnected drive means (not shown) are providedfor the shafts 114 and 115' which support the arms 107, 163 and 114, 115and it will be noted from FIGURE 7 that the racks lid-5.13 are angularlydisplaced 180 from the racks 105.

Each of the racks 1% and 1194.13 are provided with a pair of pipereceiving grooves or notches (seen at 116 and 117 in FlGURE 7) so thattwo pipes may be simultaneously handled as has been previously describedin connection with the indexing transfer units T. An internal blow outstation C, substantially identical to that seen in FIGURE 4, is alsomounted on the inclined frame 105 and the function of the indexingtransfer units T is to move the pipes from the rolls wt ltl i intoposition in alignment with the bell mouth 77 of the blow out unit, holdthe pipes in position during the blow out operation,

and then convey them on to the exit conveyor B (seen in FIGURE In theoperation of the above described apparatus pipes leaving the galvanizingkettle 19 are moved by the permanent magnet rolls Nil-134 as has beenpreviously explained. As a pipe P is moved its forward end (left inFIGURE 6) engages a limit switch (not seen in FIG- URE 6 but which mightbe similar to that shown at 59 in FIGURE 4) at a predetermined pointbefore it reaches the final position seen at P" in FIGURE 6. This limitswitch is connected to start the operation of a single revolution drivemechanism (also not shown but of any suitable type) for the transferunits T and racks 106 and llii13 thereof which, while the pipe is beingadvanced by the rolls mil-1&4 to the limit switch actuation point, arein their normal or at-rest positions as een in FIG- URE 7.

As noted above, when the end of pipe P trips the limit switch theadvance end of the pipe has not yet reached the final position seen inFIGURE 6 and the pipe continues to be moved by the rolls -1-34. However,after the racks 1% have moved through slightly more than 90 of theirsingle revolution movement they will be in position to lift the pipe orpipes P from the rolls ltit21tl4. At this time the forward end of thepipe P" will have reached the position seen in FIGURE 6. Concurrently,by a suitable switch actuated by one of the racks 106, the magneticrolls rec-m4 if of the electromagnetic type are momentarily deenergizedto facilitate the pipes being lifted therefrom by the racks 1% as theycontinue their counter-clockwise travel. As rotation of racks 106continues the pipe carried thereon will be moved laterally and at theend of a full revolution the racks 106 and 110-113 will stop in theirat-rest positions (seen in FIG- URE 7). The pipe P" will then be held bythe racks 1153-113 (as will be later explained) in alignment with thepipe receiving bell portion 77 of the blow out units C and the pipes maybe subjected to a blast of air or steam to control the interior coatingas has been previously described.

When the single revolution operating cycle of the transfer racks isagain started by actuation of the limit switch by the advancing end of anew pipe P", the racks Ht 113 will move the pipe or pipes P supportedthereon to the left (FIG. 7) away from blow out unit C and deposit sameon the conveyor B in the same manner as previously described inexplaining the operation of the racks 63 in FIGURE 5.

As the arms 197, 16 3 and 114, 115, which support the racks 1% and110-113 respectively, are the same length and as they are so spacedapart that in one point in the rotation of the two sets of racks theirpaths cross with the grooves 116 and 117 therein in alignment (see FIG-URE 8), the pipes that are lifted off of the rolls Nt 1194 by the racks106 will be picked up by the racks 119 113 at the point where thisalignment takes place. This transfer point is illustrated in FIGURE 8and it will be understood that after this occurs the racks 110-113 willcarry the pipe and continue their rotation until they are stopped attheir at-rest positions in alignment with the internal blow out unit C.The racks 1% in like manner will stop in their at-rest positions, seenin FTGURE 7, and will be ready to start another transfer cycle whenanother pipe engages the limit switch to start the single revolutionrotation of the racks.

As explained in connection with the apparatus of FIG- URE 4 this singlerevolution rotation of the transfer racks is controlled by any suitablemeans which, as it per se forms no part of the present invention, is notillustrated herein. In order to maintain the pipes in position on theracks 106 and 119413 permanent magnet inserts indicated at 118 aredisposed in the grooves 116 and 117 of at least some of the racks ofeach set.

As previously noted, the racks 1ltl1ll3 are of successively lower heightfrom the one (110) closest to the galvanizing kettle l9 outwardly. Theobject of this variation in size is to effect tilting of the pipes Pfrom the s,19e,sas

angle at which they are disposed while on the rolls 11th-- 164 and racks1% closer to a horizontal position so that, when they are deposited uponthe conveyor which transports them to the next processing station, theywill be more nearly horizontal.

The apparatus illustrated in FIGURES 6, 7 and 8 eliminates theintermediate transfer racks 66 of the embodiment shown in FIGURE 5 andalso eliminates the dropping of the pipes from the drag out rolls to thefirst set of racks which occurs when th drag out rolls are disposed ontop of the pipes as seen in FIGURE 4. Otherwise the mode of operation ofthe apparatus shown in FIGURES 6, 7 and 8 is substantially the same asthat shown in FIGURES 4 and 5.

Another form of my pipe transfer mechanism is illustrated in FIGURES 9,and 11. In common with the previously described mechanisms thisembodiment includes a frame structure 125 at the left-hand end of which(FIGURE 9) a blow out unit similar to that shown at C in FIGURES 4 and6, is adapted to be mounted (but not shown in FIGURE 9). Also mounted onthe frame 125 are a series of magnetic rolls 126, 127, 128, 129 and 13d.These rolls are adapted to be simultaneously driven at the same speed byany suitable means (not shown) and are disposed to receive coated pipesas they leave the drag out rolls 52 and 53 (see FIGURE 6) in the samemanner as the rolls M64164 of FIGURE 6. A plurality of indexing transferunits generally indicated at T" are also mounted on the frame 125between the adjacent pairs of rolls IZd-ISi).

As best seen in FIGURES 10 and 11 each of the indexing transfer units Tincludes a movable walking beam member, generally indicated at W,supported for orbital movement on arms 131 and 132 which are pivotallysecured at their outer ends to bracket members 133 and 1.3 which in turnare formed integrally with the walking beam W. The arms 132 and 133 aremounted on and adapted to be rotated by shafts 132 and 133' which aredriven by any suitable means such as the motor and gear box indicated at135.

Mounted on the supporting bar 136 of each walking beam W are three tuberacks 137, 138 and 13%, best seen in FIGURE 11, each of which has a pairof tube receiv ing grooves Mil and 141. As seen in FIGURE 11, the racks137, 138 and 139 are equally spaced on the supporting bars 136 and, whenthe shafts 132' and 133" are rotated to move the arms 131 and 132 in thedirection of the arrow in FIGURE 11 these racks will be moved incorresponding orbital paths.

Each transfer unit I" also includes a pair of stationary tube racks 142and 143 which are supported on bars 144 which in turn are carried byvertical posts 145 and 1 2-6 supported on the frame 125 (see FIGURE 11).When the walking beams W are at their at-rest positions, as seen inFIGURE 11, these stationary racks 142 and 143 are aligned with themovable racks 138 and 139. It will be observed that the rolls 12613ltand the stationary racks and 1 53 each are provided with a pair of tubereceiving grooves or notches, the grooves in roll 12% being indicated at128' and the grooves in the stationary racks 1:12 and 1435 beingindicated at 142 and M3, respectively (see FIGURE 11).

As previously noted, the at-rest position of the walking beams W isillustrated in FIGURE 11 and it will be noted that the movable rack 137is in alignment with the magnetic roll 128 but with its pipe receivinggrooves 14 and 14-1 slightly below the level of the top of the grooves128' in the roll 12%. In like manner the tube engaging grooves 14d and141 of the movable racks 138 and 139 are slightly below and in alignmentwith the grooves 142' of stationary rack 142 and 143' of stationary raci143, respectively.

In the operation of the apparatus of FIGURES 9-11, the tubes that aremoved from the coating bath by the drag out rolls 52 and 53 (seen inFIGURES 4 and 6) are carried along by the magnetic rolls 126-139 untilthe advancing end of the pipe moves beyond roll 13% into a predeterminedposition whereupon a limit switch actuated by the pipe end, or othersuitable means, initiates a single revolution movement of the shafts 132and 133' which actuate the walking beams W. Substantially concurrentlywith the starting of the rotation these shafts and the starting of themovement of the walking beams W the magnetic rolls 126-13tl aredeenergized. After the first few degrees of movement of the walkingbeams W the grooves of movable racks 137 will pick up the pipes that areon the rolls 126-139, the grooves in the movable racks 138 will pick uppipes that are on the stationary racks 142, and the grooves in themovable racks 139 will pick up pipes that are on the stationary racks143.

Referring to FIGURE 11, the pipes 147 which are on the rolls 126-134will be picked up by the racks 137 and will be transferred, at the endof of movement of the arms 131 and 132, to the grooves at 142 of thestationary racks 142. Concurrently the pipes 143 that are supported onthe stationary racks 142 (which is in alignment with the blow-outstation C at which the pipes are subjected to steam or the like underpressure to remove excess zinc from their inner surfaces) aretransferred by the movable racks 138 to the stationary racks 143. Inlike manner, and during the same movement of the walking beams W, thepipes 149 that are supported on the stationary racks 143 will be movedto the right (FIGURE 11) and will be deposited on a conveyor (not shownin FIGURE 11 but which may be similar to conveyor B seen in FIGURE 5).

After the pipes 147, 148 and 149 have been transferred during the first180 of movement of the walking beams W and their supporting arms 131 and132, the rotation continues until a single revolution of arms 131 and132 is completed. The walking beams W then stop in their at-restpositions (seen in FIGURE 11) and are ready for another pipe indexingand transferring cycle as soon as another set of pipes have been movedinto position by the rolls 126-130 and the transfer cycle has beeninitiated by the limit switch or the like referred to above. It will beunderstood that time is permitted during the advancing of another set ofpipes on the rolls 126430 for the internal blow out operation carriedout by blow out unit C to take place on the pipes when they aresupported on the stationary racks 142.

In order to prevent longitudinal movement of the pipes while on themovable and stationary racks magnetic in serts are preferably providedin some or all of these racks. It will also be understood that themagnetic rolls 126439, if of the electromagnetic type, are onlymomentarily deeuergized at the time when the movable racks 137 pick thepipes oii of these rolls. They are then re-energized so that they willbe effective in moving the pipes longitudinally out of the coating bath.If these rolls are of the permanent magnet type such deenergization ofcourse, does not occur. The apparatus of FIGURES 9, 10 and 11 willperform the same pipe indexing and transferring functions as theembodiments of the other views of the drawings. It, however, requiresonly a single orbiting member for each indexing transfer unit asdistinguished from a pair of orbiting members for each transfer unit inthe previously described embodiments.

Although the illustrated embodiments of my invention have been describedin considerable detail it will be understood that variations andmodifications may be made in the form and arrangement of the partsmaking up my improved apparatus. I do not, therefore, wish to be limitedto the exact structures and proportions herein shown and described, butclaim as my invention all em bodiments thereof coming within the scopeof the appended claims.

I claim:

1. In continuous pipe galvanizing apparatus having a plurality ofelectromagnetic rollers disposed to support and move a pipelongitudinally out of a galvanizing bath with its axis inclined andswitch means engageable by said pipe and effective upon such engagementto de-energize said rollers and release the magnetic grip thereof onsaid pipe; an indexing transfer unit disposed adjacent said rollers andincluding a pair of movable pipe carrying racks supported for movementin orbital paths the centers of which are offset from each other, astationary rack supported between said offset centers and out ofalignment with the path of said pipe when carried by said rollers,interconnected driving means for said movable racks whereby a constantangular displacement is maintained between said movable racks duringmovement thereof in said orbital paths, one of said movable racks, whenin an at-rest position, being disposed in alignment with and below saidpath of said pipe and being adapted to receive a pipe released from saidrollers, said stationary rack being disposed to receive a pipe from saidone of said movable racks after a predetermined rotation thereof fromsaid at-rest position, the path of movement of the other of said movableracks being such that a pipe deposited on said stationary rack by saidone of said movable racks will be lifted from said stationary rack bysaid other of said movable racks after a predetermined movement from itsat-rest position and transferred to a position laterally offset fromsaid stationary rack, and means for holding a pipe against longitudinalmovement on said other of said movable racks.

2. In continuous pipe galvanizing apparatus having electromagneticrollers for moving a pipe longitudinally out of a galvanizing bath, saidrollers supporting said pipe on the undersides of said rollers whereby,when said rollers are de-energized, a pipe supported thereby will dropoff said rollers; a series of indexing transfer units disposed belowsaid rollers in the path of fall of a pipe dropped therefrom, said unitseach including a pair of movable pipe carrying racks supported formovement in orbital paths the centers of which are offset from eachother; a stationary rack supported between said offset centers,interconnected driving means for said movable racks whereby a constantangular displacement of about 90 is maintained between said movableracks during movement thereof in said orbital paths, one of said movableracks being disposed belowsaid rollers when in an at-rest position atthe top of its orbital path and being adapted to receive a pipe droppedfrom said rollers, said stationary rack being disposed to receive a pipefrom said one of said movable racks after about 90 rotation thereof, thepath of movement of the other of said movable racks being such that apipe deposited on said stationary rack by said one of said movable rackswill be lifted from said stationary rack by said other of said movableracks after movement of about 180 from its at-rest position, and meanseffective on a pipe on said other movable rack when in said at-restposition for blowing excess zinc from the inside of said pipe.

3. In pipe coating apparatus having a plurality of rollers adapted tomove a pipe out of a coating bath and an internal coating controlstation adjacent said rollers; an indexing transfer unit disposedadjacent said rollers and including a first movable rack means adaptedto pick up and convey pipes from said rollers in a direction parallel tothe axes of said rollers, means for moving said first rack means in anorbital path whereby pipes removed from said rollers will be movedtransversely of their length into a position to be treated by saidinternal coating control station, a second movable rack means, and meansfor moving said second rack means concurrently with but in a differentorbital path from said first rack means, said second rack means beingadapted to move pipes away from said position concurrently with thebringing of pipes to said position by said first rack means' 4. In pipecoating apparatus having a plurality of magnetic rollers supported inspaced apart relation with their axes parallel and adapted to move pipeout of a coating bath and an internal coating control station adjacentsaid rollers; a first movable rack means disposed between an adjacentpair of said magnetic rollers and adapted to convey pipes from saidrollers in a direction parallel to the axes of said rollers, means formoving said first movable rack means in an orbital path whereby pipesremoved from said rollers will be moved transversely of their lengthinto a position to be treated by said internal coating control station,a second movable rack means adjacent said first rack means, means formoving said second rack means concurrently with but in a differentorbital path from said first rack means, said second rack means beingadapted to move pipes away from said position concurrently with thebringing of pipes to said position by said first rack means, and meansfor effecting concurrent revolution movement of both of said rack means.

5. In pipe coating apparatus having a plurality of magnetic rollerssupported in spaced apart relation with their axes parallel and adaptedto move a pipe out of a coating bath and an internal coating controlstation adjacent said rollers but spaced transversely of the path ofpipes conveyed by said rollers; an indexing transfer unit disposedbetween an adjacent pair of said magnetic rollers and including a firstmovable rack means for conveying pipes from said rollers in a directionparallel to the axes of said rollers, means for moving said first rackmeans in an orbital path whereby pipes removed from said rollers will bemoved transversely of their length into a position to be treated by saidinternal coating control station, means for holding pipes in saidposition, a second movable rack means, means for moving said second rackmeans concurrently with but in a different orbital path from said firstrack means, said second rack means being adapted to move pipes away fromsaid position concurrently with the bringing of pipes to said positionby said first rack means, and means for effecting concurrent revolutionmovement of both of said rack means.

6. In pipe coating apparatus having a plurality of rollers disposed andadapted to move a pipe longitudinally out of a coating bath with itsaxis inclined; a plurality of movable pipe carrying racks supported formovement in different orbital paths, a stationary rack laterally offsetfrom the path of a pipe carried by said rollers, driving means for saidmovable racks, a first one of said movable racks, when in an at-restposition, being disposed directly below said path of a pipe on saidrollers, said stationary rack being disposed to receive a pipe from saidfirst one of said movable racks after a predetermined rotation thereoffrom said at-rest position, the path of movement of a second one of saidmovable racks being such that a pipe deposited on said stationary rackby said first one of said movable racks will be lifted from saidstationary rack by said second one of said movable racks and transferredto a position laterally offset from said stationary rack, magnetic meansfor holding pipes on said stationary rack, and means etfective on a pipeon said stationary rack for blowing excess coating material from theinside of the pipe.

7. Pipe coating apparatus including a plurality of rollers adapted tomove a pipe longitudinally out of a coating bath, a series of three pipecarrying racks, a common support member for said racks disposed betweenan adjacent pair of said rollers and having an at-rest position, saidracks being mounted in spaced relation on said support member on a lineextending transversely of the path of movement of pipes carried by saidrollers, means for moving said support member from said at-rest positionin an orbital path whereby said racks are moved concurrently in separateorbital paths extending transversely of said path of movement of pipescarried by said rollers, one of said movable racks, when said sup-References Cited by the Examiner port member is in said at-restposition, being below said path of movement of pipes carried by saidrollers, a pair UNITED STATES PATENTS of stationary pipe supportingracks disposed one in align- 1,799,760 4/31 Moon 118-63 ment with eachof the other two of said movable racks 5 2 893 348 7 /59 Pearson 118 11when said support member is in said at-rest position,

means for imparting orbital movement to said support 2906237 9/59Bernhardt 118* member and said three movable racks, and means effec-RICHARD D NEVIUS Primary Examiner tive on a pipe on the stationary rackclosest to said rollers for blowing excess coating material from theinside of 10 JOSEPH SPENCER Examiner the pipe.

2. IN CONTINUOUS PIPE GALVANCING APPARATUS HAVING ELECTROMAGNETICROLLERS FOR MOVING A PIPE LONGITUDINALLY OUT OF A GALVANIZING BATH, SAIDROLLERS SUPPORTING SAID PIPE ON THE UNDERSIDES OF SAID ROLLERS WHEREBY,WHEN SAID ROLLERS, ARE DE-ENERGIZED, A PIPE SUPPORTED THEREBY WILL DROPOFF SAID ROLLERS; A SERIES OF INDEXING TRANSFER UNITS DISPOSED BELOWSAID ROLLERS IN THE PATH OF FALL OF A PIPE DROPPED THEREFROM, SAID UNITSEACH INCLUDING A PAIR OF MOVABLE PIPE CARRYING RACKS SUPPORTED FORMOVEMENT IN ORBITAL PATHS THE CENTERS OF WHICH ARE OFFSET FROM EACHOTHER; A STATIONARY RACK SUPPORTED BETWEEN SAID OFFSET CENTERS,INTERCONNECTED DRIVING MEANS FOR SAID MOVABLE RACKS WHEREBY A CONSTANTANGULAR DISPLACEMENT OF ABOUT 90* IS MAINTAINED BETWEEN SAID MOVABLERACKS DURING MOVEMENT THEREOF IN SAID ORBITAL PATHS, ONE OF SAID MOV-